Drones have struck an oil facility outside the Russian city of Azov, not far from the border with Ukraine, local authorities report.
Azov is located approximately eight miles from the border with Ukraine, by Lake Azov, just southwest of the larger city of Rostov-na-Don.
Images published by Russian emergency services show flames erupting from an oil facility and thick smoke rising from it.
According to an initial report from the governor of the Rostov region, Vasilij Golubev, no people have been killed in the attack. It is unclear how many drones were used, but the governor reports that 200 firefighters have been involved in attempting to extinguish the fire, which spread over 5,000 square metres.
Ukraine's security service, the SBU, is behind the attack, according to consistent reports in Ukrainian and international media. The attack was directed at two oil depots with a total of 22 silos, according to these reports.
Ukraine has carried out many similar attacks on targets in Russia, often against oil facilities. This has been discouraged on several occasions by the USA, citing the consequences it could have for the price of oil.